Answer to Question #94244 in Organic Chemistry for Kri

Question

1-3 hexadiene, 1-4 hexadiene, 1-5 hexadiene.
Order the following molecules in increasing order of stability and justify your answer.

Answer 1

A conjugated diene has a smaller heat of hydrogenation and is more stable than a similar isolated diene.

Conjugated diene is 1,3-hexadiene. It is the most stable.

$CH_2=CH-CH=CH-CH_2-CH_3$

Two other dienes are isolated.The increase in stability of 1,4-hexadiene over 1,5-hexadiene is due to the increased double bond substitution of the former.

Order of stability (the first is the most stable):

1,3-hexadiene>1,4-hexadiene>1,5-hexadiene